HELP Lisa dead 150W Power Supply

From: Scharpf Thomas <thomas_at_email.domain.hidden>
Date: Mon, 24 Dec 2001 14:24:36 +0200

Hello everybody out there,

I've a little problem with a defect 1,8 A Switching Power Supply. It doesn't work! Shame, shame! When I replace it by another the Lisa starts up, without any problems.
The unit sends the 5V Standby Output, but when pushing the Start-Button nothing happens, although all connectors are good, all switches closed and as I could test so far, something pushes the Basis of Q5 2N4001 near the Comparer LM 393 up to 0.7 V so that the Transistor lets current flow and the Collector leads Ground, this causes the Interrupt to work constantly and the unit doesn't receive the 5V Input, when pushing the Power ON and can't power up.
And/Or does somebody know, where to find a link to some schematics of power supplies, I've got one, but this isn't an equivalent one to my 150 W 1,8 A although it's described as this type of supply

...and last but not least a "merry X-mas" to you guys around the world, sent from the snowy, cold bavaria in the center of europe!

... hey, of course to you old Ladies, too: all LISA's

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Received on 2001-12-26 22:22:13

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